Sims Medieval won't open

I've had a physical copy of "The Sims Medieval" for over a decade now, and previously, it ran just fine on my desktop PC. I stepped away from it for a while, stopped playing, but when I found "Pirates and Nobles", I downloaded it and tried to boot up the base game, but it refuses to open now. I've tried everything to get it to run, but it won't, it just sits at my desktop homepage, and doesn't show it running at all in Task Manager. I did a full uninstall-reinstall, and it didn't work, it still won't open. My PC is running Windows 8, if that at all helps. If anyone's got any words of wisdom, that'd be appreciated!